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If you saw this while browsing Tor you went to an onion hosted by Freedom Hosting. The javascript exploit was injected into your browser if you had javascript enabled.

What the exploit does:

The JavaScript zero-day exploit that creates a unique cookie and sends a request to a random server that basically fingerprints your browser in some way, which is probably then correlated somewhere else since the cookie doesn’t get deleted. Presumably it reports the victim’s IP back to the FBI.

FBI Hidden Service in connection with the JavaScript exploit:
7ydnpplko5lbgfx5

Who’s affected Time scales:

Anyone who accessed an FH site in the past two days with JavaScript enabled. Eric Eoin Marques was arrested on Sunday so that’s the earliest possible date.

“In this paper we expose flaws both in the design and implementation of Tor’s hidden services that allow an attacker to measure the popularity of arbitrary hidden services, take down hidden services and deanonymize hidden services
Trawling for Tor Hidden Services: Detection, Measurement, Deanonymization”

On any other day one would say these sick perverts got what they deserved. Unfortunately the Feds are stepping far beyond just pedophiles in this latest issue.

The js inserted at Freedom Hosting? Nothing really, just an iframe inject script with a UUID embedded server-side.

The iframe then delivers an exploit kit that appears to be a JavaScript 0day leading to…something. It only attempts to exploit Firefox (17 and up) on Windows NT. There’s definitely some heap spraying and some possible shell code. The suspect shell code block contains some strings that look to formulate an HTTP request, but I haven’t been able to collect the final payload yet. The shell code also contains the UUID with which the exploit was delivered. Any UUID will work to get this part of the exploit.

I’m still pulling this little bundle of malware apart. So far, I’ve got that the attack is split across three separate files, each loaded into an iframe. Calls are made between the frames to further obfuscate the control flow. The ‘content_2.html’ and ‘content_3.html’ files are only served up if the request “looks like” Firefox and has a correct Referer header. The ‘content_2.html’ is loaded from the main exploit iframe and in turn loads ‘content_3.html’.

Short version. Preliminary analysis: This little thing probably CAN reach out without going through Tor. It appears to be exploiting the JavaScript runtime in Firefox to download something.

UPDATE: The exploit only affects Firefox 17 and involves several JS heap-sprays. Note that the current Extended Support Release is Firefox 17, so this may also affect some large organizations using Firefox ESR.

The script will only attempt the exploit on Firefox 17, so I’m no longer worried about it being some new 0day. Enough of the “Critical” MFSAs are for various sorts of memory corruption that I don’t have the time to find out if this is actually a new exploit or something seen before.

Logical outcomes from this?

1. FBI/NSA just shut down the #1 biggest hosting site and #1 most wanted person on Tor

2. Silkroad is next on their list, being the #2 most wanted (#1 was Child Porn, #2 is drugs)

3. Bitcoin and all crypto currenecies set to absolutely CRASH as a result since the feds can not completely control this currency as they please.

I don’t always call the Feds agenda transparent, but when i do, I say they can be trying harder.